1. Field of the Invention
The invention relates in general to printed circuit board, and more particularly to printed circuit board having grounding conductive pillar.
2. Description of the Related Art
To avoid distortion of signal, a trace layer of a conventional printed circuit board (such as double-layered printed circuit board) is formed on the same side. If the trace layer is required to form on another side, the two opposite trace layer are connected by a conductive via.
However, it is helpless in promoting quality of transmitting high speed signal by purely using conductive via connecting the two opposite trace layer; contrarily, the impedance of transmission signal become inconsistent. For example, a difference of the impedance along transmission signal path becomes large.